Forgive my ignorance but what is a psp2 and what type of balanced output does it have? Transformer? electronic? If its electronic you should tie pin 3&1 together providing that the output of the preamp is pin 2 hot... If its not then pin 2&1 should be tied together if its a transformer output you can use pin 2 as hot pin 3 as negative and pin 1 floating connected to one side of the shield at the output end of the chain. I suspect it might be that this preamp is pin 3 hot not pin 2 if that is the case you would increase the distortion of the preamp significantly by tying pin 3 to ground. Not to mention the fact that you would be inverting the output 180 degrees.
Thanks Chris!
The psp2 is a preamp that was made by a now defunct French company so there really isn't any factory support. The inputs are transformer based but I don't *think* the outputs are.
I have not heard distortion in the samples that were at a reasonable level. They sound good.
My cable currently ties 1&3 together. Any suggestion on how I can determine which of 2 or 3 are hot using a DVM? I thought they were both hot in a balanced config with one of them being out of phase. I just tried to measure the dc voltage between 1&2 and 1&3 (nothing on the inputs). They both measured about .13 volts and were the same polarity (positive with ground neg).
Now... I did find this troubling comment about cabling the psp2 unbalanced.. it definitely gives me pause and I am trying to interpret it. I had read it before but my initial results with my unbal cable were good so I dismissed it:
one thing about the xlr interconnects for the psp2. This was relayed to me by Art Munson or Frank , I can't remember which. I've had two of these things and I fried the first one. I traded the hulk in on a NOS unit that was found for me. I got a call at work one day and Art/Frank told me to make sure that only two wires were soldered to the xlr connector. The third one was left free. I'm no xlr expert so details are fuzzy.
When they say two wires only, I assume they mean 1 to shield and 2 as the signal with 3 being left open (could be 2 open, 3 sig).. So that implies the shield is connected at both ends. Wondering if shield connected at both ends is preferable to shield tied at one end only and using a wire for the ground.
I use the 1804a for this because it is small and nice to use but I suppose an unbalanced cable would be better? If I'm only using one wire and shield I imagine the quad is not ideal.
The psp2 does have an 1/8 unbalanced output and, gee, it does seem to work. I assumed I would get higher quality output with my own cable on the separate bal outs.